[master] RFR: 8314863: [Lilliput] Revert changes in zRelocate, prevent ZGC with Lilliput

[Aleksey Shipilev]

On Wed, 23 Aug 2023 08:42:01 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

> The additions of SuspendibleThreadSet in [zRelocate.cpp](https://builds.shipilev.net/patch-openjdk-lilliput/src/hotspot/share/gc/z/zRelocate.cpp.udiff.html) can cause deadlocks. This problem can not easily be solved without major work in Lilliput. Let's revert those changes and prevent usage of ZGC together with Lilliput.
> 
> Testing:
>  - [ ] hotspot_gc +UCOH
>  - [ ] hotspot_gc -UCOH (default)

Minor nit, otherwise looks good.

src/hotspot/share/runtime/arguments.cpp line 3101:

> 3099:       FLAG_SET_DEFAULT(UseCompactObjectHeaders, false);
> 3100:     } else {
> 3101:       fatal("Incompatible options: +UseZGC can not currently be used together with +UseCompactObjectHeaders");

I think this should be `vm_exit_during_initialization`, not `fatal`.

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Marked as reviewed by shade (Committer).

PR Review: https://git.openjdk.org/lilliput/pull/107#pullrequestreview-1591088442
PR Review Comment: https://git.openjdk.org/lilliput/pull/107#discussion_r1302698970